Fabric take-up for a flat knitting machine



FABRIC TAKE-UP FOR A FLAT KNITTING MACHINE Original Filed May 29, 1956 3 Sheets-Sheet 1 INVENTOR.

72217 [62%272 WWW Jan. 12, 1960 A. J. coBERT 7 2,920,463

FABRIC TAKE-UP FOR A FLAT KNITTING MACHI NE Original Filed May 29, 1956 3 Sheets-Sheet 2 INVENTOR.

Jan. 12, 1960 A. J. COBERT FABRIC TAKE-UP FOR A FLAT KNITTING MACHINE 3 Sheets-Sheet 3 Original Filed May 29, 1956 INVENTO /flizm/ $21? a w sinker supportbar 40.

United States Patent FABRIC TAKE-UP FOR A FLAT KNITTING MACHINE Arthur J. Cobert, Chattanooga, Tenn., assignor of fifty percent to Beautiful Bryans, Incorporated, Chattanooga,

Tenn., a corporation of Tennessee Original application May 29, 1956, Serial No. 588,157, now Patent No. 2,853,863, dated September 30, 1958. Divided and this application January 10, 1958, Serial No. 708,091

4 Claims. (11. 66-152) The present invention relates to an improved fabric take-up for a flat knitting machine and is herein disclosed as embodied in a fiat full-fashioned type knitting machine adapted for the knitting of a Welt fabric.

This application is a division of an application of Arthur J. Colbert, Serial No. 588,157, filed May 29, 1956, in the United States Patent Ofiice for Method and Apparatus To Draw Off a Fold of Welt Fabric, and issued as Patent No. 2,853,863, dated September 30, 1958.

It is a principal object of the invention to provide a novel and improved nip roller take-up for a flat knitting machine comprising a pair of nip rollers and support arms on which the nip rollers are adapted to be moved from an initial fabric engaging position adjacent the needles to a relatively withdrawn take-up position away from the needles which provides for a continued stepped rotational take-up movement of the nip rollers well adapted to maintain at all times a continuous even takeup of the fabric.

With this and other objects in view as may hereinafter appear, the several features of the invention consist in devices, combinations and arrangement of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a sectional view in side elevation of a straight bar knitting machine adapted for the knitting of fullfashioned hosiery, showing particularly one of the supporting frames and the various shaft centers, and more particularly the fabric take-up mechanism which forms more specifically the subject matter of the invention;

Fig. 2 is a view in front elevation illustrating generally the mechanism shown in Fig. l, and including two adjacent knitting sections of the machine with their adjacent supporting frames; and

Fig. 3 is an isometric exploded view of the nip roller take-up mechanism of the machine.

The straight bar knitting machine which is generally illustrated in the drawings as embodying in a preferred form the several features of my invention is a so-called cotton type. full-fashioned hosiery machine having a series of spring beard needles 20 movable as a unit, yarn measuring sinkers 22 adapted to be moved successively in a knitting wave by means of a slur cock 24 for sinking yarn successively about the shanks of the needles 20,

and a series of web holders or knock-over bits, not here specifically shown.

The machine is further provided with a narrowing machine including the usual narrowing machine frame bar 26, and forwardly extending rocker arm supports 28 from which are supported narrowing fingers 30. The supporting structure for the machine includes cross frames 34 spaced one to each two sections of the machine,

and longitudinally extending frame members including a rear tie rod 36, a lower front frame member 38 and a There is also shown in the illustrated machine a series of overhead frame supports 44, which are mounted as upward extensions of respective frame members 34 and provide support for an overhead welt mechanism including a series of hanging welt bar support levers having mounted thereon welt hook bars adapted to be manipulated with relation to the knitting instrumentalities for setting up, drawing off, and subsequently in cooperation with transfer elements, for returning an initial course of welt loops to the needles to close the welt. Inasmuch as the welt mechanism referred to forms no part of this invention and is fully described in applicants co-pending application, above referred to, no particular description or illustration thereof is made in this application.

In the illustrated form of the invention shown a nip roller take-up is provided to engage with the fold of welt fabric which may be produced as set forth for example in applicants co-pending application Serial No. 588,157 above referred to, by the operation of the welt bar and the welt wire take-up thereafter described.

The nip roller is particularly adapted to take over from the welt wire take-up the function of drawing oif the knitted fabric as it is produced, said draw-off action being continued untilthe stocking blank is fully knitted and is finally pressed off of the needles. As best shown in Figs. 1, 2 and 3 of the drawings the nip roller take-up comprises a pair of upwardly extending nip roller support levers 46, 48 pivotally supported at their lower ends by means of bearing pins on brackets 50 and 52 which are mounted from the lower front rail 38. At their upper ends each of the lever arms 46 and 48 is journaled to receive a rotatable shaft 54 on which is mounted .a lower nip roller 56. The lever arms 46 and 48 are securely tied together by means of a connecting rod 58 which also provides a pivotal support for two short lever arms 59 and 60 which, at their outer ends, have secured thereto a connecting rod 62. An upper nip roller 64 is mounted to turn freely on the rod 62. Tension springs 66 connected respectively between the short lever arm 59 and lever support 58 between the arm 60 and lever 46 act to maintain the nip rollers yieldably in contact with one another. Each of the nip rollers 56 and 64 is made of any simple material as, for example, hollow plastic tubes which are covered with a layer of sponge rubber and provided with a knitted cotton cover. The tubes are preferably constructed with aluminum flanges at each end which are cut out to provide bearing surfaces for supporting and rotating the rollers on respective shafts 62 and 54. The lower roller 56 is connected to its shaft 54 by means of a torsion spring 68 which, while connecting the roll to turn the shaft, permits the roll to vibrate with each successive forward and back movement of the needles in the knitting of successive courses.

Mechanism is provided for imparting a stepped rotational movement to the roller 56 which comprises the ratchet 70 mounted on the shaft 54 and a cooperating pawl 72 carried on the upwardly extending arm of a T- shaped pawl lever 74 loosely supported to turn on shaft 54. A lock pawl 75 prevents movement of the ratchet 70 in a reverse direction. The pawl 74 receives its motion through a flexible cable 76 and lever arm 78 secured to the usual regulator shaft 80 of the machine. The regulator shaft 80 is connected to be oscillated with each rotation of the main cam shaft of the machine indicated at 82 (Fig. 1) in' order to control the forward and back position of the needles during one portion of each stitchforming cycle, and it is this oscillatory movement which is applied to effect a stepped advancing movement of the pawl 72 and ratchet 70 to advance the nip roller 56 during the knitting of each successive course. .The arrangement of the mechanism for imparting a stepped drawing off movement to the nip rollers 46 and 56 above described ratchet 70 by a downward movement of the lever arm 78 and is then allowed to return by spring pressure as the Bowden Wire 76 is slackened by the return movement of lever arm 78. Advancing movement of the pawl 72 is effected by means of a spring 86 connected between a forwardly extending arm of the pawl lever 74 and a lever 88 pivoted at 90 on nip roller support lever 46. The take-up tension exerted upon the fabric, and also the extent of each successive increment of take-up is thus controlled by the tension of spring 86 and is at the same time automatically adjusted in accordance with the length of fabric knitted.

With the illustrated construction I provide an improved mechanism for varying automatically the amount of tension exerted upon the fabric by the spring 86 during the knitting of different portions of the stocking blank. In general a heavy tension is applied during the knitting of the wide upper leg portions and a gradually reduced tension is applied as the fabric is narrowed toward the heel and foot. The mechanism provided (see Fig. 3) consists of cam and follower connections mounted on a fixed portion of the machine for controlling the angular position of lever 88 on the nip roller support lever 46 and thereby the tension exerted by spring 86. The lever 88 is connected with a tension pull rod 92, which extends longitudinally of the machine near the rear rail 36, by means of a Bowden wire 94 connected at one end to the tension control lever 88 and at its other end to a collar 96 on the tension pull rod 92.

The position of the tension pull rod 92 (see Fig. 3) is in turn controlled by means of a cam 98 supported to turn on a fixed pivot 100 on the machine. A depending cam follower lever 102 mounted to turn on a fixed pivot 104 and provided with a cam follower roll 106 is engaged at its lower end between two collars 108 fixed for the tension pull rod 92 which is thus controlled by the cam 98. A spring 110 acting against the pull rod 92 serves to maintain the follower rail 106 at all times in engagement with the cam 93. The angular position of cam 98 is controlled by means of connections which are responsive to movement of the yarn carrier stops in accordance with the width of fabric being knitted. A pinion 112 secured to the cam 100 engages a rack 114 which forms part of a slide rod 116 connected by means of a lever am 118 with one of the carrier dead stop blocks 120 of the carrier stop control mechanism of the machine.

The nip roller assembly, including the nip roller, support levers 46, 48 and nip rollers 56, 64 is moved between a. normal take-up position shown in dotted lines in Fig. 1 withdrawn from the needles, and a rearward close-tothe-needles position shown in full lines in Fig. l for engaging the fold of welt fabric drawn off by the welt wire Y take-up. The nip roller take-up assembly is moved positively rearwardly to the full line position of Fig. l in which the nip take-up rollers 56, 64 (Fig. 3) are moved to a position adjacent their needles by means of a cable 124 (Fig. 1) connected with nip take-up lever 46 by means of a tension spring 126 connected between the cable wire and a horizontally disposed arm 128. At its rear end the cable 124 is fixed to a pulley 130 secured to a shaft 132 which also has secured thereon one element of a magnetic clutch 134. The other element of the clutch having secured thereto a sprocket, not specifically illustrated, is adapted to receive a sprocket chain 138 which also passes around the sprocket 140 secured to a transmission shaft 142 extending along the rear side of the machine. The shaft 142 is driven from an electric motor 144 by means of a sprocket chain 146 which passes '4 around sprockets on the armature shaft of the motor and on the transmission shaft 142. When the magnetic clutch is energized by means not specifically shown the cable wire 124 is wound onto its sprocket causing the nip roller assembly to be drawn rearwardly to its extreme rearward position in which a latch 148 engages in a notch lock dial 150 to lock the assembly in this position. An adjustable stop 152 (Fig. 3) is arranged to engage an upper portion of lever arm 46 for the rearward position of the nip roller take-up assembly to more rigidly hold the frame members including levers 46 and 48 in position as the latch 148 drops into its locking position. In the engagement of the notch lock dial 150, the limit switch 154 thus opens the clutch 134 thus preventing any further movement upon the cable wire 124.

In the operation of the machine the magnetic clutch 156 is energized at some point prior to the beginning of the take-up operation to move the nip roller take-up assembly to its rearward full-line position shown in Fig. 1. After a fold of welt fabric has been formed and has been drawn between nip rollers, and after an additional five or six inches of fabric has been knitted to avoid any possibility that the fabric may be pulled out from between the nip rollers the latch 148 is automatically withdrawn from the lock dial 150 thus permitting the nip roller supporting assembly to fall outwardly under the influence of its own weight, further assisted by the pressure of spring 126 so that the entire assembly hangs upon the fabric. As additional fabric is knitted the nip roller support levers 46, 48 swing outwardly until the assembly reaches the dotted line position of Fig. l in which the nip roller support lever 46 engages against a fixed stop 158 on the machine.

The invention having been described what is claimed 1. In a flat knitting machine adapted for knitting welt fabrics having a series of knitting needles, the combination of a nip roller fabric take-up mechanism which com prises a pair of support arms arranged to turn as a unit about a fixed pivot, a nip roller rotatably supported on said arms, a cooperating nip roller, and means movably supporting said cooperating nip roller from said support arms in yieldable engagement with said first mentibned nip roller, means operative during fabric knitting for swinging said pivoted support arms to move the nip rollers between a fabric receiving position adjacent the needles and a relatively retracted take-up position remote from the needles, a ratchet connected with one of said rollers, an oscillatory pawl mechanism cooperating with said ratchet mounted from one of said lever arms, a continuously oscillating member on a fixed portion of the machine, and connections between said oscillating member and the pawl mechanism for oscillating said pawl mechanism to impart a stepped fabric feeding movement to said roller.

2. A nip roller fabric take-up mechanism for a flat knitting machine according to claim 1 having a yieldable driving connection between the ratchet and the first mentioned nip roller, a pawl and pawl actuating lever supported concentrically with said ratchet on one of said lever arms, and spring means for moving said pawl lever and pawl in a direction to advance the ratchet and nip roller connected therewith, and connections between the oscillating member and pawl lever for imparting successive positive retracting movements to the pawl lever and pawl.

3. A nip roller fabric take-up mechanism for a flat knitting machine according to claim 2 having means for adjusting said spring means for moving said pawl lever and pawl in a direction to advance the ratchet to vary the draw-off tension upon the fabric drawn oif from the needles by said nip roller 4. A nip roller fabric take-up mechanism for a flat knitting machine according to claim 3 in which the spring pawl actuating means is acted upon by connections which include a member connected to said spring means, a tension pull rod supported on a fixed portion of the machine, a flexible connection connecting the said member and tension pull rod, and a cam and follower connection for controlling the position of the tension pull rod, and means operating during the knitting of the fabric to position said cam and follower connection.

References Cited' in the file of this patent UNITED STATES PATENTS Childrey June 17, 1913 Houseman Nov. 18, 1913 Ballard Oct. 31, 1916 Pecker Nov. 14, 1922 Wirth Dec. 15, 1936 Lambach May 18, 1954 

